WO2022267970A1 - Optical gyroscope and noise reduction method - Google Patents

Abstract

An optical gyroscope, which is applied to the field of detection. The optical gyroscope comprises a light source assembly (101), a first light beam transmission loop (105), a second light beam transmission loop (106), a first photoelectric detector (109) and a second photoelectric detector (110). The light source assembly (101) is used for generating a first light beam and a second light beam which are different from each other. The first light beam transmission loop (105) is used for transmitting the first beam in a clockwise direction while transmitting the second beam in a counterclockwise direction. The second light beam transmission loop (106) is used for transmitting the first beam in a counterclockwise direction while transmitting the second beam in a clockwise direction. The first photoelectric detector (109) is used for receiving the combined first light beam. The second photoelectric detector (110) is used for receiving the combined second light beam. The light beam transmission loops can simultaneously transmit light beams in opposite directions, such that the optical gyroscope can reduce noise during a detection process to improve the detection precision.

Description

Optical Gyroscope and Noise Reduction Method

This application claims priority to a Chinese patent application with application number "202110692950.5" and application title "Optical Gyroscope and Noise Reduction Method" filed with the China Patent Office on June 22, 2021, the entire contents of which are incorporated herein by reference Applying.

technical field

The application relates to the field of detection, in particular to an optical gyroscope and a noise reduction method.

Background technique

Gyroscopes are used to detect rotational motion. Among them, the optical gyroscope detects rotational motion through the Sagnac effect. But in the detection process, there may be noise. Noise is random fluctuations in the source signal or beam delivery loop. In practical applications, noise will affect the signal from the Sagnac effect (referred to as Sagnac signal for short), thereby reducing the detection accuracy of the optical gyroscope.

Contents of the invention

The application provides an optical gyroscope and a noise reduction method. In this application, the noise in the detection process can be reduced and the detection accuracy can be improved by allowing the light beam transmission loop of the optical gyroscope to simultaneously transmit light beams in opposite directions.

The first aspect of the present application provides an optical gyroscope. The optical gyroscope includes a light source component, a first beam transmission loop, a second beam transmission loop, a first optical coupler, a second optical coupler, a first photodetector and a second photodetector. Wherein, the light source component is used to generate different first light beams and second light beams. Specifically, the wavelengths of the first light beam and the second light beam are different, and/or, the polarization states of the first light beam and the second light beam are orthogonal. The first light beam transmission loop is used to transmit the first light beam in a clockwise direction while transmitting the second light beam in a counterclockwise direction. The second beam transmission loop is used to transmit the first beam in a counterclockwise direction while transmitting the second beam in a clockwise direction. The first optical coupler is used for combining the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop. The first photodetector is used to receive the combined first light beams to obtain a first electrical signal. The first electrical signal is also referred to as a first gyroscope signal. The second optical coupler is used for combining the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop. The second photodetector is used to receive the combined second beams to obtain a second electrical signal. The second electrical signal is also referred to as a second gyroscope signal. The first gyroscope signal and the second gyroscope signal can be used for noise cancellation.

In this application, by allowing the beam transmission loop to simultaneously transmit clockwise and counterclockwise beams, the detection efficiency can be improved and the delay can be reduced on the basis of noise elimination. Also, the first light beam and the second light beam are different. Therefore, the present application can reduce the influence of the interference phenomenon between the first light beam and the second light beam in the light beam transmission loop on the gyroscope signal, and improve the detection accuracy.

In an optional manner of the first aspect, the first light beam transmission loop is used to transmit the first light beam in a clockwise direction during the first transmission time period, while transmitting the second light beam in a counterclockwise direction. The first light beam transmission loop is also used to transmit the first light beam in a counterclockwise direction during the second transmission time period. The second light beam transmission loop is used for transmitting the first light beam in a counterclockwise direction during the first transmission time period, while transmitting the second light beam in a clockwise direction. The second beam transmission loop is also used to transmit the first beam in a clockwise direction during the second transmission time period. The second optical coupler is used for combining the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the first transmission time period. The second optical coupler is also used to combine the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the second transmission time period. The second photodetector is used for receiving the combined second light beam during the first transmission time period. The second photodetector is also used to receive the combined first light beams during the second transmission period to obtain a third electrical signal. The third electrical signal is also referred to as a third gyroscope signal.

Wherein, the noise with the same sign in the first electrical signal and the second electrical signal is called reciprocal noise. In practical applications, non-reciprocal noise with opposite signs may be carried in the first electrical signal and the second electrical signal. Since the signs of the Sagnac signal in the first electrical signal and the second electrical signal are opposite, that is, the Sagnac signal and the nonreciprocal noise are in the same direction, the nonreciprocal noise cannot be eliminated by the first electrical signal and the second electrical signal. In this application, the transmission direction of the first light beam is changed to try to make the sign of the non-reciprocal noise and the Sagnac signal the same, thereby eliminating the non-reciprocal noise. Therefore, performing noise elimination through the first electrical signal, the second electrical signal and the third electrical signal can further reduce the influence of noise and improve detection accuracy.

In an optional manner of the first aspect, the first light beam transmission loop is also used to transmit the second light beam in a clockwise direction during the second transmission time period. The second light beam transmission loop is also used to transmit the second light beam in a counterclockwise direction during the second transmission time period. The first optical coupler is used for combining the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the first transmission time period. The first optical coupler is also used for combining the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the second transmission time period. The first photodetector is used for receiving the combined first light beam during the first transmission time period. The first photodetector is also used to receive the combined second light beams during the second transmission period to obtain a fourth electrical signal. The fourth electrical signal is also referred to as a fourth gyroscope signal. In this application, the transmission direction of the second light beam is changed, and the sign of the non-reciprocal noise in the second gyroscope signal and the fourth gyroscope signal are tried to be reversed, so as to eliminate the non-reciprocal noise again. In this application, it can be understood as the average of two non-reciprocal noises that are eliminated. Therefore, the detection accuracy can be further improved.

In an optional manner of the first aspect, the optical gyroscope further includes an optical switch. The optical switch includes a first input port, a second input port, a first output port and a second output port. The first input port is used for receiving the first light beam generated by the light source assembly. The second input port is used for receiving the second light beam generated by the light source assembly.

In the first transmission period, in the first transmission period, the first input port is connected to the first output port, the first output port is connected to the first end of the first beam transmission loop, and the second end of the second beam transmission loop The second input port is connected to the second output port, and the second output port is connected to the second end of the first beam transmission loop and the first end of the second beam transmission loop. The first light beam transmission loop is used to receive the first light beam through the first end, transmit the first light beam in a clockwise direction, and simultaneously receive the second light beam through the second end, and transmit the second light beam in a counterclockwise direction. The second light beam transmission loop is used for receiving the first light beam through the second end, transmitting the first light beam in a counterclockwise direction, and simultaneously receiving the second light beam through the first end, and transmitting the second light beam in a clockwise direction.

During the second transmission period, the second input port is connected to the first output port. The first output port is connected to the second end of the first beam transmission loop and the first end of the second beam transmission loop. The first input port is connected to the second output port. The second output port is connected to the first end of the first beam transmission loop and the second end of the second beam transmission loop. The first light beam transmission loop is used for receiving the first light beam through the second end, and transmitting the first light beam in a counterclockwise direction. The second light beam transmission loop is used for receiving the first light beam through the first end and transmitting the first light beam in a clockwise direction. Similarly, during the second transmission time period, the first light beam transmission loop is also used to receive the second light beam through the first port, and transmit the second light beam in a clockwise direction. The second light beam transmission loop is used for receiving the second light beam through the second end, and transmitting the second light beam in a counterclockwise direction. Among them, changing the transmission direction of the light beam through the optical switch can reduce the number of lasers, thereby reducing the cost.

During the second transmission period, the second input port is connected to the first output port. The first output port is used to output the second light beam. The first input port is connected to the second output port. The second output port is used to output the first light beam. The first light beam transmission loop is used for receiving the first light beam through the second output port, and transmitting the first light beam in a counterclockwise direction. The second beam transmission loop is used for receiving the first beam through the second output port, and transmitting the first beam clockwise. Similarly, during the second transmission time period, the first light beam transmission loop is also used to receive the second light beam through the first output port, and transmit the second light beam in a clockwise direction. The second light beam transmission loop is used for receiving the second light beam through the first output port, and transmitting the second light beam in a counterclockwise direction. Among them, changing the transmission direction of the light beam through the optical switch can reduce the number of lasers, thereby reducing the cost.

In an optional manner of the first aspect, the light source component includes a laser and a polarization beam splitter (Polarization Beam Splitter, PBS). A laser is used to generate the target beam. The polarizing beam splitter is used to split the target beam into a first beam and a second beam with orthogonal polarization states. Using a polarizing beam splitter can reduce the number of lasers and thus reduce the cost.

In an optional manner of the first aspect, the light source component includes a laser and a wave splitter. Lasers are used to generate target beams with multiple wavelengths. The wave splitter is used to split the target beam into a first beam and a second beam. The first light beam and the second light beam have different wavelengths. Among them, by using a wave splitter, the number of lasers can be reduced, thereby reducing costs.

In an optional manner of the first aspect, the first beam transmission loop and the second beam transmission loop are planar spiral waveguides. Among them, the integrated spiral waveguide can reduce the volume of the optical gyroscope and improve the stability of the structure.

In an optional manner of the first aspect, the first beam transmission loop and the second beam transmission loop are helical polarization-maintaining optical fibers. Among them, the loss of polarization maintaining fiber is lower. Therefore, the number of turns of the light beam transmission loop can be more, thereby improving the detection accuracy.

In an optional manner of the first aspect, the helical directions of the first beam transmission loop and the second beam transmission loop are opposite. Wherein, when the helical directions of the first beam transmission loop and the second beam transmission loop are opposite, the two first beams or the two second beams always enter the beam transmission loop through the same entrance. For example, when a first beam enters the first beam transmission loop from the inner circle of the first beam transmission loop, another first beam enters the second beam transmission loop from the inner circle of the second beam transmission loop . When a first light beam enters the first light beam transmission loop from the outer circle of the first light beam transmission loop, another first light beam enters the first light beam transmission loop from the outer circle of the first light beam transmission loop. Therefore, when the helical directions of the first beam transmission loop and the second beam transmission loop are opposite, the transmission paths of the two first beams are similar, thereby reducing the influence of noise on the Sagnac effect signal and improving detection accuracy.

In an optional manner of the first aspect, the first beam transmission loop is located on the first plane. There is an overlapping area between the projection of the second beam transmission loop on the first plane and the first beam transmission loop. Wherein, by arranging the first light beam transmission loop and the second light beam transmission loop on different planes, the volume of the optical gyroscope can be reduced, thereby reducing the cost.

In an optional manner of the first aspect, the optical gyroscope further includes a third photodetector and a controller. The third photodetector is used to measure the power of the first light beam before the first light beam enters the first light beam transmission loop to obtain the first optical power. The controller is used for adjusting the output power of the light source assembly according to the first light power. Among them, the output of the laser may fluctuate due to the influence of temperature. Fluctuating output can affect detection accuracy. In this application, the output of the laser is adjusted through feedback, which can reduce fluctuations, thereby improving the accuracy of detection.

The second aspect of the present application provides a noise reduction method. The noise reduction method is applied to the optical gyroscope. The noise reduction method includes the following steps: the optical gyroscope generates different first light beams and second light beams. The wavelengths of the first light beam and the second light beam are different, and/or, the polarization states of the first light beam and the second light beam are orthogonal. Wherein, the optical gyroscope includes a first beam transmission loop and a second beam transmission loop. The first beam travels clockwise in the first beam delivery loop while the second beam travels counterclockwise in the first beam delivery loop. And, the first light beam is transmitted counterclockwise in the second light beam transmission loop, while the second light beam is transmitted clockwise in the second light beam transmission loop. The optical gyroscope acquires a first electrical signal of the first beam passing through the first beam delivery loop and the second beam delivery loop. The optical gyroscope acquires a second electrical signal of the second beam passing through the first beam delivery loop and the second beam delivery loop. The optical gyroscope eliminates the interference signal according to the first electrical signal and the second electrical signal to obtain the target electrical signal.

In an optional manner of the second aspect, the first electrical signal and the second electrical signal are acquired during the first transmission time period. The noise reduction method further includes: the optical gyroscope acquires a third electrical signal of the first light beam passing through the first light beam transmission loop and the second light beam transmission loop during the second transmission time period. Wherein, in the second transmission time period, the first light beam is transmitted counterclockwise in the first light beam transmission loop, while the first light beam is transmitted clockwise in the second light beam transmission loop. The optical gyroscope obtains the target electrical signal according to the first electrical signal, the second electrical signal and the third electrical signal.

In an optional manner of the second aspect, the optical gyroscope divides the sum of the first electrical signal and the second electrical signal by two to obtain the first interference signal. The optical gyroscope subtracts the first interference signal from the first electrical signal to obtain the first target electrical signal. The optical gyroscope subtracts the first interference signal from the third electrical signal to obtain the third target electrical signal. The optical gyroscope divides the difference between the first target electrical signal and the third target electrical signal by two to obtain the target electrical signal. Wherein, the sign of the reciprocal noise in the first electrical signal and the second electrical signal is the same. Therefore, by dividing the sum of the first electrical signal and the second electrical signal by two, the first interference signal (also called reciprocal noise) can be obtained. The non-reciprocal noise has the same sign in the first electrical signal and the third electrical signal. Non-reciprocal noise can be eliminated by subtracting the first electrical signal of interest from the third electrical signal of interest. Therefore, the present application can eliminate reciprocal noise and non-reciprocal noise in electrical signals, and improve detection accuracy.

In an optional manner of the second aspect, the noise reduction method further includes: the optical gyroscope acquires a fourth electrical signal of the second light beam passing through the first light beam transmission loop and the second light beam transmission loop during the second transmission time period. Signal. Wherein, in the second transmission time period, the second light beam is transmitted clockwise in the first light beam transmission loop, while the second light beam is transmitted counterclockwise in the second light beam transmission loop. The optical gyroscope obtains the target electrical signal according to the first electrical signal, the second electrical signal, the third electrical signal and the fourth electrical signal.

In an optional manner of the second aspect, the optical gyroscope subtracts the first electrical signal from the second electrical signal to obtain the first difference. The optical gyroscope subtracts the third electrical signal from the fourth electrical signal to obtain a second difference. The optical gyroscope divides the sum of the first difference and the second difference by four to obtain the target electrical signal. Wherein, the reciprocal noise has the same sign in the first electrical signal and the second electrical signal, and in the third electrical signal and the fourth electrical signal. Therefore, reciprocity noise can be eliminated by subtracting the first electrical signal from the second electrical signal, and the third electrical signal from the fourth electrical signal. The non-reciprocal noise has the same sign in the first electrical signal and the third electrical signal, and in the second electrical signal and the fourth electrical signal. Non-reciprocal noise can be removed by adding the first difference to the second difference. In this application, it can be understood as the average of two non-reciprocal noises that are eliminated. Therefore, the detection accuracy can be further improved.

In an optional manner of the second aspect, the optical gyroscope acquires the first light beam and the second light beam in the following manner. An optical gyroscope generates the target beam. The optical gyroscope splits the target beam into first and second beams with orthogonal polarization states.

In an optional manner of the second aspect, the optical gyroscope acquires the first light beam and the second light beam in the following manner. Optical gyroscopes generate target beams with multiple wavelengths. The optical gyroscope splits the target beam into a first beam and a second beam. Wherein, the first light beam and the second light beam have different wavelengths.

In an optional manner of the second aspect, the noise reduction method further includes: before the first light beam enters the first light beam transmission loop, the optical gyroscope measures the power of the first light beam to obtain the first optical power. The optical gyroscope adjusts the output power of the light source assembly according to the first optical power.

Description of drawings

Fig. 1 is the first structural schematic diagram of optical gyroscope;

Fig. 2 is the second structural schematic diagram of the optical gyroscope provided in the present application;

Fig. 3 is the third structural schematic diagram of the optical gyroscope provided in the present application;

Fig. 4 is the first schematic diagram of the gyroscope signal changing with temperature provided in the present application;

Fig. 5 is the second schematic diagram of the gyroscope signal changing with temperature provided in the present application;

Fig. 6 is the fourth schematic structural view of the optical gyroscope provided in the present application;

FIG. 7 is a schematic structural diagram of the beam transmission loop provided in the present application;

Fig. 8 is the fifth schematic diagram of the optical gyroscope provided in the present application;

FIG. 9 is a schematic flowchart of a noise reduction method provided in this application.

detailed description

The application provides an optical gyroscope and a noise reduction method. In this application, the noise in the detection process can be reduced and the detection accuracy can be improved by allowing the light beam transmission loop of the optical gyroscope to simultaneously transmit light beams in opposite directions. It should be understood that "first", "second" and the like used in the present application are only used for the purpose of distinguishing and describing, and cannot be interpreted as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, reference numerals and/or letters are repeated in the various figures of this application for the sake of brevity and clarity. Repetition does not imply a strictly limited relationship between the various embodiments and/or configurations.

Optical gyroscopes are used to detect rotational motion. However, noise will reduce the detection accuracy of the optical gyroscope. Therefore, the influence of noise can be reduced by the two gyroscope signals. Figure 1 is a schematic diagram of the first structure of an optical gyroscope. As shown in Figure 1, the optical gyroscope includes a light source 101, an optical switch 102, a directional coupler 103, an optical coupler 104, a beam transmission loop 105, a beam transmission loop 106, an optical coupler 107, a directional coupler 108, a photoelectric detector 109 and photodetector 110 .

The optical gyroscope works periodically. In the first half period, the laser light generated by the light source 101 enters the path a after passing through the optical switch 102 . Afterwards, the optical coupler 104 acts as a beam splitter to split the laser light into two laser beams. One laser beam travels counterclockwise in the optical transmission path 105 , and the other laser beam travels clockwise in the optical transmission path 106 . The optical coupler 107 acts as a beam combiner to combine the two laser beams. The directional coupler 108 couples the combined laser beams to a photoelectric detector (Photoelectric detector, PD) 109 . The photodetector PD 109 obtains the first gyroscope signal by demodulating the combined laser beams. In the second half period, the laser light generated by the light source 101 enters the path b after passing through the optical switch 102 . Afterwards, the optical coupler 107 acts as a beam splitter to split the laser light into two laser beams. One laser beam travels clockwise in the optical transmission path 105 , and the other laser beam travels counterclockwise in the optical transmission path 106 . The optical coupler 104 acts as a beam combiner to combine the two laser beams. The directional coupler 104 couples the combined laser light to the photodetector PD 110. The photodetector PD 110 obtains the second gyroscope signal by demodulating the combined laser beams. In the first gyroscope signal and the second gyroscope signal, the sign of the Sagnac signal is opposite, and the sign of the noise is the same. Therefore, the effect of noise can be reduced by the two gyroscope signals (referred to as noise reduction).

In order to reduce noise, the above-mentioned optical gyroscope increases the detection of the second half cycle, thus doubling the detection time and increasing the delay. In practical applications, the lower the latency of the optical gyroscope, the better.

For this reason, the present application provides another optical gyroscope. FIG. 2 is a second structural schematic diagram of the optical gyroscope provided in this application. As shown in Figure 2, the optical gyroscope includes a light source assembly 201, a beam transmission loop 205, a beam transmission loop 206, an optical coupler 207 (also referred to as a second optical coupler), an optical coupler 204 (also referred to as a second optical coupler) an optical coupler), photodetector 208 (also referred to as a second photodetector) and photodetector 209 (also referred to as a first photodetector).

The light source assembly 201 is used to generate a first light beam and a second light beam. The first light beam enters the optical coupler 207 through the path b. The optical coupler 207 is used to split the first light beam to obtain two first light beams. The two first beams respectively enter different beam transmission loops. Specifically, one of the first beams is transmitted clockwise in the beam transmission loop 205 (also referred to as the first beam transmission loop). Another first beam is transmitted counterclockwise in the beam delivery loop 206 (also referred to as the second beam delivery loop). Conversely, the second light beam enters the optical coupler 204 via path a. The optical coupler 204 is used to split the second light beam to obtain two second light beams. The two second beams respectively enter different beam transmission loops. Specifically, one of the second beams is transmitted counterclockwise in the beam transmission loop 205 . Another second beam is transmitted counterclockwise in the beam delivery loop 206 .

After outputting from the beam delivery loop, the two first beams enter the optical coupler 204 . The optical coupler 204 is used to combine the two first light beams. The optical coupler 204 is also used to couple the combined first light beam to the photodetector 209 . The photodetector 209 is used to obtain a first electrical signal according to the combined first light beams. Conversely, the two second beams enter the optical coupler 207 after outputting from the beam delivery loop. The optical coupler 207 is used to combine the two second light beams. The optical coupler 207 is also used to couple the combined second light beam to the photodetector 208 . The photodetector 208 is used to obtain a second electrical signal according to the combined second light beams.

In the beam transmission loop, the transmission directions of the first beam and the second beam are opposite. Therefore, the sign of the Sagnac signal is opposite in the first electrical signal and the second electrical signal. Also, the sign of the noise is the same. Therefore, noise can be canceled by two electrical signals. For the specific calculation process, please refer to the subsequent noise reduction method.

For any beam delivery loop, the beam delivery loop simultaneously transmits the first beam and the second beam in opposite transmission directions. In the beam transmission loop, the beam traveling in the clockwise direction and the beam traveling in the counterclockwise direction may interfere with each other. Interference phenomena can reduce the accuracy of the Sagnac signal. For this reason, in the application, the first light beam and the second light beam are different. Specifically, the wavelengths of the first light beam and the second light beam are different, and/or, the polarization states of the first light beam and the second light beam are orthogonal. Therefore, the present application can reduce the influence of the interference phenomenon between the first light beam and the second light beam in the light beam transmission loop on the Sagnac signal, and improve the detection accuracy.

It should be understood that due to differences in physical structures, such as the lengths of path a and path b, the moment when the first light beam and the second light beam enter the light beam transmission loop may be different. Therefore, "simultaneously" means that there is an overlapping region in the time range of beam transmission. For example, the time range during which the first light beam is transmitted in the first light beam transmission loop is the first interval. The time range during which the second light beam is transmitted in the first light beam transmission loop is the second interval. The simultaneous transmission of the first light beam and the second light beam by the first light beam transmission loop means that there is an overlapping area between the first interval and the second interval.

In practical applications, two lasers may be used in order to generate different first and second beams. Two lasers generate a first beam and a second beam, respectively. However, in order to reduce the number of lasers and reduce the cost of the optical gyroscope, the embodiment of the present application provides two exemplary structures of the optical component 201 .

In an example, as shown in FIG. 2 , the light source assembly 201 includes a laser 202 and a polarization beam splitter 203 . The laser 202 may be a distributed feedback laser (Distributed Feedback Laser, DFB). Laser 202 is used to generate a target beam. The polarization beam splitter 203 is used to split the target beam into a first beam and a second beam with orthogonal polarization states. In another example, the light source component 201 includes a laser and a wave splitter. The laser can be a Fabry-Perot FP laser or a mode-locked laser. Lasers are used to generate target beams with multiple wavelengths. The wave splitter is used to split the target beam into a first beam and a second beam. The first light beam and the second light beam have different wavelengths. For example, when the target beam has 10 wavelengths, the first beam has 6 of them, and the second beam has 6 of them. Wherein, the first light beam and the second light beam have the same wavelength. In order to further reduce the influence of the interference phenomenon on the Sagnac signal, the first light beam and the second light beam may have completely different wavelengths. For example, when the target beam has 10 wavelengths, the first beam has 5 of them, and the second beam has the other 5 wavelengths.

In this application, the noise with the same sign in the first electrical signal and the second electrical signal is called reciprocal noise. In practical applications, non-reciprocal noise with opposite signs may be carried in the first electrical signal and the second electrical signal. The signs of the Sagnac signal and the nonreciprocal noise are in the same direction, so the nonreciprocal noise cannot be eliminated by the first electrical signal and the second electrical signal.

For this reason, in other embodiments, the present application changes the transmission directions of the first light beam and the second light beam, trying to make the sign of the non-reciprocal noise and the Sagnac signal the same. FIG. 3 is a third structural schematic diagram of the optical gyroscope provided in this application. As shown in FIG. 3 , the optical gyroscope includes a light source assembly 201 , an optical switch 301 , a beam transmission loop 205 , a beam transmission loop 206 , an optical coupler 207 , an optical coupler 204 , a photodetector 208 and a photodetector 209 .

The light source assembly 201 is used to generate a first light beam and a second light beam. The optical switch 301 is used to implement optical crossing. Specifically, the optical switch 301 includes a port 1 , a port 2 , a port 3 and a port 4 . Wherein, port 1 is also called a first input port, port 2 is also called a second input port, port 3 is also called a second output port, and port 4 is also called a first output port. Port 1 is used to receive the first light beam generated by the light source assembly 201 . Port 2 is used to receive the second light beam generated by the light source assembly 201 .

During the first transmission period, port 1 and port 4 are connected. Port 4 is used to output the first light beam. The first light beam enters the optical coupler 207 through the path b. The optical coupler 207 is used to split the first light beam to obtain two first light beams. The two first beams respectively enter different beam transmission loops. After outputting from the beam delivery loop, the two first beams enter the optical coupler 204 . The optical coupler 204 is used to combine the two first light beams. The optical coupler 204 is also used to couple the combined first light beam to the photodetector 209 . The photodetector 209 is used to obtain a first electrical signal according to the combined first light beams.

During the first transmission time period, port 2 and port 3 are connected. Port 3 is used to output the second beam. The second light beam enters the optical coupler 204 through the path a. The optical coupler 204 is used to split the second light beam to obtain two second light beams. The two second beams respectively enter different beam transmission loops. After outputting from the beam delivery loop, the two second beams enter the optical coupler 207 . The optical coupler 207 is used to combine the two second light beams. The optical coupler 207 is also used to couple the combined second light beam to the photodetector 208 . The photodetector 208 is used to obtain a second electrical signal according to the combined second light beams.

During the second transmission period, port 1 and port 3 are connected. Port 3 is used to output the first light beam. The first light beam enters the optical coupler 204 through the path a. The optical coupler 204 is used to split the first light beam to obtain two first light beams. The two first beams respectively enter different beam transmission loops. Specifically, one of the first beams is transmitted counterclockwise in the beam transmission loop 205 . Another first beam is transmitted clockwise in the beam transmission loop 206 . After outputting from the beam delivery loop, the two first beams enter the optical coupler 207. The optical coupler 207 is used to combine the two first light beams. The optical coupler 207 is also used to couple the combined first light beam to the photodetector 208 . The photodetector 208 is used to obtain a third electrical signal according to the combined first light beams.

During the second transmission period, port 2 and port 4 are connected. Port 4 is used to output the second light beam. The second light beam enters the optical coupler 207 through path b. The optical coupler 207 is used to split the second light beam to obtain two second light beams. The two second beams respectively enter different beam transmission loops. Specifically, one of the second beams is transmitted clockwise in the beam transmission loop 205 . Another second beam is transmitted counterclockwise in the beam delivery loop 206 . After outputting from the beam delivery loop, the two second beams enter the optical coupler 204 . The optical coupler 204 is used to combine the two first light beams. The optical coupler 204 is also used to couple the combined first light beam to the photodetector 209 . The photodetector 209 is used to obtain a fourth electrical signal according to the combined second light beams.

Reciprocal noise and non-reciprocal noise can be eliminated through the obtained first electrical signal, second electrical signal, third electrical signal and/or fourth electrical signal, and the accuracy of detection can be improved. For the specific calculation process, please refer to the subsequent noise reduction method.

In this application, the optical gyroscope may periodically acquire the first electrical signal, the second electrical signal, the third electrical signal and/or the fourth electrical signal. Specifically, the optical gyroscope acquires the first electrical signal and the second electrical signal in the first half cycle. The optical gyroscope acquires the third electrical signal and the fourth electrical signal in the second half cycle. At this time, the first transmission time period is the first half of a cycle, referred to as the first half cycle; the second transmission time period is the second half of a cycle, referred to as the second half cycle.

Wherein, the optical gyroscope that generates the first electrical signal is called a forward gyroscope, and the optical gyroscope that generates the second electrical signal is called an inverse gyroscope. Reciprocal noise for forward and reverse gyroscopes. In forward and reverse gyroscopes, the sign of the reciprocal noise is the same. Non-reciprocal noise is for the first half cycle and the second half cycle. In the first half cycle, the nonreciprocal noise and the Sagnac signal have the same sign. In the second half cycle, the non-reciprocal noise and the Sagnac signal have opposite signs when changing the direction of transmission of the beam.

It should be understood that the optical gyroscope shown in FIG. 2 or FIG. 3 is just an example. In practical applications, those skilled in the art can make adaptive changes according to requirements. The adaptively changed optical gyroscope still belongs to the protection scope of the present application. Adaptive changes include, but are not limited to, any one or more of the following.

For example, in FIG. 2 or FIG. 3 , the optical coupler 204 is used to realize the functions of beam splitting and beam combining. The optical coupler 204 is also used to couple the combined beams to the photodetectors. In practical applications, as shown in Figure 1, the optical gyroscope also includes a directional coupler. The optical coupler 204 is used to realize the functions of beam splitting and beam combining. The directional coupler is used to couple the combined beams to the photodetectors.

For example, in FIG. 3 , the light source assembly 201 includes a laser 202 and a polarizing beam splitter 203 . The light source assembly 201 is used to generate different first light beams and second light beams. The optical switch 301 is used to realize the optical crossing of the first light beam and the second light beam. In practical applications, the optical gyroscope includes a first laser, a second laser, a third laser, a fourth laser, a first beam combiner and a second beam combiner. The first laser is used to generate the first light beam in the first half cycle. The second laser is used to generate a second light beam during the first half cycle. Similarly, a third laser is used to generate the second beam during the second half cycle. The fourth laser is used to generate the first beam in the second half cycle. The first beam combiner is used to couple the beams generated by the first laser and the third laser into path b. The second beam combiner is used to couple the beams generated by the second laser and the fourth laser into path a. Wherein, in the first half period, the third laser and the fourth laser do not generate light beams. During the second half cycle, the first laser and the second laser do not generate beams.

In practical applications, the output power of the laser may fluctuate due to the influence of the ambient temperature. Fluctuating power can affect detection accuracy. Fig. 4 is the first schematic diagram of the gyroscope signal changing with temperature provided in this application. The abscissa of Fig. 4 is time, and the ordinate is power or temperature. Wherein, the ordinate of the power curve is power, and the ordinate of the temperature curve is temperature. FIG. 4 includes a power curve 401 of the first electrical signal, a power curve 402 and a temperature curve 403 of the second electrical signal. As shown in FIG. 4 , the power curve 401 and the power curve 402 change as the temperature curve 403 changes.

For this reason, the present application can adjust the output power of the laser through feedback regulation. Specifically, as shown in FIG. 3 , the optical gyroscope may further include a photodetector 302 (also referred to as a third photodetector) and a controller 303 . The photodetector 302 is used to measure the power of the first light beam before the first light beam enters the light beam transmission loop to obtain the first light power. The controller 303 may be a processor. The processor may be a general-purpose central processing unit (central processing unit, CPU), a microprocessor, or the like. The controller 303 is configured to adjust the output power of the light source assembly 201 according to the first optical power. For example, when the first optical power is greater than the target power, the controller 303 reduces the output power of the light source assembly 201; when the second optical power is less than the target power, the controller 303 increases the output power of the light source assembly 201. FIG. 5 is a second schematic diagram of the gyroscope signal changing with temperature provided in this application. FIG. 5 includes a power curve 501 of the first electrical signal, a power curve 502 and a temperature curve 503 of the second electrical signal. As shown in FIG. 5 , the power curve 501 and the power curve 502 do not change as the temperature curve 503 changes. Therefore, the present application can reduce power fluctuations by adjusting the output power of the laser through feedback, thereby improving the accuracy of detection.

Similarly, the optical gyroscope may also include a fourth photodetector. FIG. 6 is a fourth structural schematic diagram of the optical gyroscope provided in this application. As shown in Figure 6, the optical gyroscope includes a light source assembly 201, a beam transmission loop 205, a beam transmission loop 206, an optical coupler 207, an optical coupler 204, a photodetector 208, a photodetector 209, and a photodetector 302 , a photodetector 606 (also referred to as a fourth photodetector), an optical coupler 602 and an optical coupler 603 .

Wherein, the light source assembly 201 includes a laser 2021 and a laser 2022 . The laser 2021 is used to generate the first light beam, and the laser 2022 is used to generate the second light beam. The optical coupler 602 is used to couple the first light beam into the photodetector 302 . The photodetector 302 measures the power of the first light beam to obtain the first light power. The controller is used to adjust the output power of the laser 2021 according to the first optical power. The optical coupler 603 is used to couple the second light beam into the photodetector 606 . The photodetector 606 is used to measure the power of the second light beam to obtain the second light power. The controller is used to adjust the output power of the laser 2022 according to the second optical power. Regarding the transmission paths of the first light beam and the second light beam in the light beam transmission loop, reference may be made to the description of the aforementioned FIG. 2 or FIG. 3 .

In other embodiments, the first beam delivery loop and the second beam delivery loop are planar spiral waveguides. The planar spiral waveguide is integrated on the substrate. The shape of the waveguide can conform to an Archimedes spiral. The specific inner ring radius and the number of turns of the waveguide are designed according to the loss of the waveguide. The width and height of the waveguide are designed according to the quality requirements of the transmitted beam. For example, in FIG. 6, beam delivery loop 205 and beam delivery loop 206 are an example of a planar spiral waveguide. The material of the planar spiral waveguide can be silicon nitride SiN, silicon Si, or silicon dioxide SiO ₂ .

In order to improve detection accuracy, the helical directions of the beam transmission loop 205 and the beam transmission loop 206 can be opposite. Wherein, when the helical directions of the beam transmission loop 205 and the beam transmission loop 206 are opposite, the two first beams or the two second beams always enter the beam transmission loop through the same entrance. Take the first beam as an example. When a first beam enters the beam transmission loop 205 from the outer circumference of the beam transmission loop 205 , another first beam enters the beam transmission loop 206 from the outer circumference of the beam transmission loop 206 . After changing the transmission directions of the first light beam and the second light beam, when a first light beam enters the light beam transmission loop 205 from the inner circle of the light beam transmission loop 205, another first light beam enters the light beam transmission loop 205 from the inner circle of the light beam transmission loop 206 The inner ring enters the beam delivery loop 206 . When two beams enter the beam delivery loop according to the same entrance, the delivery paths of the beams are more similar, thereby improving the accuracy of the Sagnac signal.

When the beam transmission loop 205 and the beam transmission loop 206 are planar spiral waveguides, in order to reduce the loss at the crossing point, the planar spiral waveguide and the input waveguide may be in different planes. As shown in FIG. 6 , the optical gyroscope also includes an input waveguide 604 and an input waveguide 605 (shown in dashed lines in FIG. 6 ). If the input waveguide 604 and the beam transmission loop 205 are on the same plane, there are many crossing points between the input waveguide 604 and the beam transmission loop 205 . Crossing points reduce the power of the beam. Similarly, if the input waveguide 605 and the beam transmission loop 206 are on the same plane, there are many crossing points between the input waveguide 605 and the beam transmission loop 206 . In order to reduce the loss at the crossing point, the beam transmission loop 205 and the input waveguide 604 are in different planes, and the beam transmission loop 206 and the input waveguide 605 are in different planes.

In practical applications, due to inconsistent lengths of the manufactured waveguides between the beam transmission loop 205 and the beam transmission loop 206, there may be a phase difference between the beams in the two beam transmission loops. The phase difference reduces the accuracy of the Sagnac signal. To this end, the optical gyroscope may also include one or more modulators 601 . The modulator 601 is used to adjust the phase of the beam transmitted in the beam transmission loop. Modulator 601 may be a thermo-optic modulator or an electro-optic modulator. The modulator 601 can be combined with the detection result of the photodetector 208 or the photodetector 209 to realize feedback regulation, so that the output corresponding to the gyroscope signal is a constant value. Hereinafter, it will be described by taking the modulator 601 as an example of a thermo-optic modulator.

When the modulator 601 is energized and heated, the refractive index of the waveguide changes, so that the phase of the light transmitted in the waveguide changes. Modulation modes of the modulator 601 include open-loop modulation and closed-loop modulation.

Open-loop modulation can be understood as biasing the operating point. Assuming that the gyroscope is not rotating, the light intensity of the second light beam reaching the photodetector 208 at a certain moment is expressed as I=I ₀ cos(Φ). When the lengths of the double helical waveguides are inconsistent, Φ≠0. At this time, the light intensity is not the maximum value. On the contrary, by adjusting the driving voltage of the modulator 601 , the light intensity detected by the photodetector 208 reaches the maximum value, that is, the phase difference Φ=0. At this time, the light intensity detected by the photodetector 209 also approximately reaches the maximum value. There may be some difference between the two maximum values. The difference is due to the difference between the first beam and the second beam. During the subsequent processing, the first electrical signal and the second electrical signal may be compensated through the difference. For example, after obtaining the first electrical signal and the second electrical signal, the difference is added to the first electrical signal. When the gyroscope rotates, the light intensity change is detected by the photodetector 208, and the change value of the phase difference based on Φ=0 is obtained. Similarly, by adjusting the driving voltage of the modulator 601, Φ=π/2 can be made. At this time, the gradient of light intensity detected by the photodetector 208 is the largest, and the sensitivity of the gyroscope is the highest.

Closed-loop modulation is on the basis of open-loop, by performing feedback adjustment to the modulator 601, the output of the gyroscope during rotation is also at the maximum value of light intensity (or the position where the rate of change of light intensity is maximum, Φ=π/2 ). For example, the output of the photodetector 208 is detected when the gyroscope operates at a biased operating point of Φ=0 or Φ=π/2. If the light intensity output by the photodetector 208 changes, the modulation voltage of the modulator 601 is adjusted through the feedback system, so that the light intensity detected by the photodetector 208 remains at the position of Φ=0 or Φ=π/2.

In the optical gyroscope, the beam transmission loop occupies a larger space, resulting in a larger volume of the optical gyroscope. For this purpose, the first beam delivery loop and the second beam delivery loop can be arranged overlapping. For example, FIG. 7 is a schematic structural diagram of a light beam transmission loop provided in this application. As shown in FIG. 7 , the optical gyroscope includes a beam delivery loop 205 and a beam delivery loop 206 . The beam delivery loop 205 is in the first plane. The beam delivery loop 206 is in the second plane. Wherein, the first plane is the top of the cuboid, and the second plane is the bottom of the cuboid. The projection of the beam transmission loop 206 on the first plane overlaps with the projection of the beam transmission loop 205 . It should be understood that when the first beam transmission loop and the second beam transmission loop are overlapped, the helical directions of the first beam transmission loop and the second beam transmission loop may be opposite. At this time, the detection accuracy can be improved on the basis of reducing the volume of the optical gyroscope. In order to reduce the loss of the light beam in the light beam transmission loop, the first light beam transmission loop and the second light beam transmission loop may be helical polarization-maintaining optical fibers. FIG. 8 is a fifth schematic diagram of the optical gyroscope provided in this application. As shown in Figure 8, the optical gyroscope includes a light source assembly 201, a beam transmission loop 205, a beam transmission loop 206, an optical coupler 207, an optical coupler 204, a photodetector 208, a photodetector 209, and a photodetector 302 , photodetector 606, optocoupler 602 and optocoupler 603. Wherein, the light source assembly 201 includes a laser 2021 and a laser 2022 . For the description of the functions of the various structures in the optical gyroscope, please refer to the related descriptions in the aforementioned FIG. 2 , FIG. 3 or FIG. 6 . In FIG. 8 , the beam transmission loop 205 and the beam transmission loop 206 are helical polarization-maintaining fibers. Moreover, in order to reduce the volume of the optical gyroscope, two polarization-maintaining optical fibers are overlapped.

The optical gyroscope provided in this application is described above. The noise reduction method provided in this application is described below. FIG. 9 is a schematic flowchart of a noise reduction method provided in this application. As shown in Figure 9, the noise reduction method includes the following steps.

In step 901, an optical gyroscope generates a first light beam and a second light beam.

The optical gyroscope generates the first light beam and the second light beam through the light source component. The first light beam and the second light beam are different. Specifically, the wavelengths of the first light beam and the second light beam are different, and/or, the polarization states of the first light beam and the second light beam are orthogonal. The optical gyroscope splits the first light beam into two first light beams. One of the first beams is transmitted clockwise in the first beam transmission loop of the optical gyroscope, and the other first beam is transmitted counterclockwise in the second beam transmission loop. The optical gyroscope splits the second light beam into two second light beams. One of the second beams is transmitted counterclockwise in the first beam transmission loop, and the other second beam is transmitted clockwise in the second beam transmission loop.

In step 902, the optical gyroscope acquires a first electrical signal of the first beam passing through the first beam transmission loop and the second beam transmission loop. The optical gyroscope combines the two first beams output from the first beam transmission loop and the second beam transmission loop. The optical gyroscope acquires the first electrical signal of the combined first beam.

In step 903, the optical gyroscope acquires a second electrical signal of the second light beam passing through the first light beam transmission loop and the second light beam transmission loop. The optical gyroscope combines the two second beams output from the first beam transmission loop and the second beam transmission loop. The optical gyroscope acquires the second electrical signal of the combined second light beam. It should be understood that there is no strict timing limitation between step 902 and step 903 .

In step 904, the optical gyroscope eliminates the interference signal according to the first electrical signal and the second electrical signal to obtain the target electrical signal. Wherein, S1=(A+B), S2=(-A+B). S1 is the first electrical signal, and S2 is the second electrical signal. A is the Sagnac signal. B is reciprocal noise. The reciprocal noise has the same sign in the first electrical signal and the second electrical signal. The signs of the Sagnac signal in the first electrical signal and the second electrical signal are opposite. Therefore, the difference between the first electrical signal and the second electrical signal is divided by two to obtain the target electrical signal.

According to the foregoing description of the optical gyroscope in FIG. 3 , it can be seen that the optical gyroscope can change the transmission directions of the first light beam and the second light beam. In the first half period, the optical gyroscope acquires the first electrical signal and the second electrical signal. In the second half period, the optical gyroscope acquires the third electrical signal and/or the fourth electrical signal. At this time, the first gyroscope signal and the second gyroscope signal may carry non-reciprocal noise with opposite signs. Let S1=(A+B+C), S2=(-A+B-C), S3=(-A+B+C), S4=(A+B-C). Wherein, S1 is the first electrical signal, S2 is the second electrical signal, S3 is the third electrical signal, and S4 is the third electrical signal. C is non-reciprocal noise. The optical gyroscope can acquire the target electrical signal according to the first electrical signal, the second electrical signal, the third electrical signal and/or the fourth electrical signal. Described below respectively.

The optical gyroscope can acquire the target electrical signal according to the first electrical signal, the second electrical signal, and the third electrical signal. The optical gyroscope divides the sum of the first electrical signal and the second electrical signal by two to obtain the first interference signal. The first interference signal is also referred to as reciprocal noise B. The optical gyroscope subtracts the first interference signal from the first electrical signal to obtain the first target electrical signal. The first target electrical signal is denoted as A+C. The optical gyroscope subtracts the first interference signal from the third electrical signal to obtain the third target electrical signal. The third target electrical signal is expressed as -A+C. The optical gyroscope divides the difference between the first target electrical signal and the third target electrical signal by two to obtain the target electrical signal. The target electrical signal is the Sagnac signal A.

The optical gyroscope can acquire the target electrical signal according to the first electrical signal, the second electrical signal, the third electrical signal, and the fourth electrical signal. The optical gyroscope subtracts the first electrical signal from the second electrical signal to obtain a first difference. The first difference is expressed as 2A+2C. The optical gyroscope subtracts the third electrical signal from the fourth electrical signal to obtain a second difference. The second difference is expressed as 2A-2C. The optical gyroscope divides the sum of the first difference and the second difference by four to obtain the target value. The target value is the Sagnac signal A.

In the foregoing, this application provides some forward-looking thinking on the noise reduction method in the optical gyroscope. This application cannot exhaust all calculation methods. Therefore, the calculations in the above denoising methods are just examples. In practical applications, those skilled in the art can make adaptive changes according to the above calculation methods. Adaptive changes include, but are not limited to, any one or more of the following.

For example, in the foregoing calculation method, for convenience of description, it is defined that the Sagnac signal and noise in the first half cycle are the same as the Sagnac signal and noise in the second half cycle. In practical application, S1=(A1+B1+C1), S2=(-A1+B1-C1), S3=(-A2+B2+C2), S4=(A2+B2-C2). Among them, A1 and A2 are Sagnac signals. B1 and B2 are reciprocal noise. C1 and C2 are non-reciprocal noise.

For example, in the aforementioned calculation method, the optical gyroscope eliminates the non-reciprocal noise through the third electrical signal and the fourth electrical signal to obtain the target electrical signal. In practical applications, non-reciprocal noise may not be carried in electrical signals. At this time, the optical gyroscope can acquire the target electrical signal according to the first electrical signal, the second electrical signal, the third electrical signal, and the fourth electrical signal. E.g. S1=(A1+B1), S2=(-A2+B1), S3=(-A3+B2), S4=(A4+B2). Among them, A1, A2, A3 and A4 are Sagnac signals. The optical gyroscope obtains the first signal through S1 and S2. The first signal is expressed as (A1+A2)/2. Optical gyroscope gets noise B2 through S3 and S4. Optical gyroscopes get A3 and A4 through B2. The optical gyroscope compares A3, A4 and the first signal for comparison. The target electrical signal of the second half cycle is determined according to the comparison result. For example, if the difference between A3 and the first signal is greater than the first threshold, and the difference between A4 and the first signal is smaller than the first threshold, then A4 is determined as the target electrical signal.

It should be understood that, for related descriptions in the noise reduction method, reference may be made to the description of the optical gyroscope in FIG. 2 , FIG. 3 , FIG. 6 or FIG. 8 . Similarly, for related descriptions about the optical gyroscope, reference may also be made to related descriptions in the noise reduction method.

The above is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application, and should cover Within the protection scope of this application.

Claims (19)

1. An optical gyroscope, characterized in that it includes: a light source assembly, a first beam transmission loop, a second beam transmission loop, a first optical coupler, a second optical coupler, a first photodetector and a second photoelectric detectors, where:

   The light source assembly is used to generate a first light beam and a second light beam;

   The wavelengths of the first light beam and the second light beam are different, and/or, the polarization states of the first light beam and the second light beam are orthogonal;

   The first light beam transmission loop is used to transmit the first light beam in a clockwise direction while transmitting the second light beam in a counterclockwise direction;

   The second light beam transmission loop is used to transmit the first light beam in a counterclockwise direction while transmitting the second light beam in a clockwise direction;

   The first optical coupler is used to combine the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop;

   The first photodetector is used to receive the combined first light beam;

   The second optical coupler is used to combine the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop;

   The second photodetector is used for receiving the combined second light beam.
2. The optical gyroscope according to claim 1, wherein,

   The first beam transmission loop is used to transmit the first beam in a clockwise direction, while transmitting the second beam in a counterclockwise direction specifically includes: the first beam transmission loop is used to transmit the first beam at the first transmission time transmitting the first light beam in a clockwise direction while transmitting the second light beam in a counterclockwise direction;

   The first light beam transmission loop is further configured to transmit the first light beam in a counterclockwise direction during a second transmission time period;

   The second light beam transmission loop is used to transmit the first light beam in a counterclockwise direction, while transmitting the second light beam in a clockwise direction specifically includes: the second light beam transmission loop is used to transmit the first light beam in the first The transmission period transmits the first light beam in a counterclockwise direction while transmitting the second light beam in a clockwise direction;

   The second beam transmission loop is further configured to transmit the first beam in a clockwise direction during the second transmission time period;

   The second optical coupler for combining the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop specifically includes: the second optical coupler is used for Combining the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop in the first transmission time period;

   The second optical coupler is also used to combine the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the second transmission time period;

   The second photodetector for receiving the combined second light beam specifically includes: the second photodetector for receiving the combined second light beam during the first transmission time period;

   The second photodetector is also used for receiving the combined first light beam during the second transmission time period.
3. The optical gyroscope according to claim 2, wherein,

   The first light beam transmission loop is further configured to transmit the second light beam in a clockwise direction during the second transmission time period;

   The second light beam transmission loop is further configured to transmit the second light beam in a counterclockwise direction during the second transmission time period;

   The first optical coupler for combining the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop specifically includes: the first optical coupler is used for Combining the first light beams transmitted by the first light beam transmission loop and the second light beam transmission loop in the first transmission time period;

   The first optical coupler is further configured to combine the second light beams transmitted by the first light beam transmission loop and the second light beam transmission loop during the second transmission time period;

   The first photodetector for receiving the combined first light beam specifically includes: the first photodetector for receiving the combined first light beam during the first transmission time period;

   The first photodetector is also used for receiving the combined second light beam during the second transmission time period.
4. The optical gyroscope according to claim 2 or 3, wherein the optical gyroscope further comprises an optical switch, and the optical switch comprises a first input port, a second input port, a first output port and a second output port, where:

   The first input port is used to receive the first light beam generated by the light source component, and the second input port is used to receive the second light beam generated by the light source component;

   During the first transmission period, the first input port is connected to the first output port, the first output port is connected to the first end of the first beam transmission loop, and the second beam transmission The second end of the loop is connected, the second input port is connected to the second output port, the second output port is connected to the second end of the first beam transmission ring, the second beam transmission ring connected to the first ends of the road;

   During the second transmission period, the second input port is connected to the first output port, the first output port is connected to the second end of the first beam transmission loop, and the second beam transmission The first end of the loop is connected, the first input port is connected to the second output port, the second output port is connected to the first end of the first beam transmission loop, the second beam transmission ring connected to the second end of the road.
5. The optical gyroscope according to any one of claims 1 to 4, wherein the light source assembly includes a laser and a polarization beam splitter, wherein:

   said laser is used to generate a target beam;

   The polarization beam splitter is used for splitting the target light beam into the first light beam and the second light beam with orthogonal polarization states.
6. The optical gyroscope according to any one of claims 1 to 4, wherein the light source assembly includes a laser and a wave splitter, wherein:

   the laser is used to generate a target beam having a plurality of wavelengths;

   The wave splitter is used to split the target light beam into the first light beam and the second light beam, wherein the first light beam and the second light beam have different wavelengths.
7. The optical gyroscope according to any one of claims 1 to 6, wherein the first beam transmission loop and the second beam transmission loop are planar spiral waveguides.
8. The optical gyroscope according to any one of claims 1 to 6, wherein the first beam transmission loop and the second beam transmission loop are helical polarization-maintaining optical fibers.
9. The optical gyroscope according to claim 7 or 8, wherein the helical directions of the first beam transmission loop and the second beam transmission loop are opposite.
10. The optical gyroscope according to any one of claims 1 to 9, wherein the first beam transmission loop is in a first plane;

    The projection of the second light beam transmission loop on the first plane overlaps with the projection of the first light beam transmission loop.
11. The optical gyroscope according to any one of claims 1 to 10, wherein the optical gyroscope further comprises a third photodetector and a controller;

    The third photodetector is used to measure the power of the first light beam before the first light beam enters the first light beam transmission loop to obtain the first optical power;

    The controller is used for adjusting the output power of the light source assembly according to the first optical power.
12. A noise reduction method applied to an optical gyroscope, characterized in that it comprises:

    generating a first light beam and a second light beam, the wavelengths of the first light beam and the second light beam are different, and/or the polarization states of the first light beam and the second light beam are orthogonal;

    Wherein, the optical gyroscope includes a first beam transmission loop and a second beam transmission loop, the first beam transmits clockwise in the first beam transmission loop, while the second beam transmits clockwise in the The first beam transmission loop is transmitted counterclockwise; the first beam is transmitted counterclockwise in the second beam transmission loop, while the second beam is transmitted clockwise in the second beam transmission loop;

    acquiring a first electrical signal of the first beam passing through the first beam delivery loop and the second beam delivery loop;

    acquiring a second electrical signal of the second beam passing through the first beam delivery loop and the second beam delivery loop;

    Eliminating interference signals according to the first electrical signal and the second electrical signal to obtain a target electrical signal.
13. The noise reduction method according to claim 12, wherein:

    The obtaining the first electrical signal of the first beam passing through the first beam transmission loop and the second beam transmission loop includes: acquiring the first electrical signal during a first transmission time period;

    The obtaining the second electrical signal of the second beam passing through the first beam transmission loop and the second beam transmission loop includes: acquiring the second electrical signal during a first transmission time period;

    The method also includes:

    acquiring a third electrical signal of the first beam passing through the first beam delivery loop and the second beam delivery loop during the second delivery time period;

    Wherein, during the second transmission time period, the first light beam is transmitted counterclockwise in the first light beam transmission loop, while the first light beam is transmitted clockwise in the second light beam transmission loop;

    The eliminating the interference signal according to the first electrical signal and the second electrical signal, and obtaining the target electrical signal includes: obtaining the Target electrical signal.
14. The noise reduction method according to claim 13, wherein said obtaining said target electrical signal according to said first electrical signal, said second electrical signal and said third electrical signal comprises:

    dividing the sum of the first electrical signal and the second electrical signal by two to obtain a first interference signal;

    subtracting the first interference signal from the first electrical signal to obtain a first target electrical signal;

    subtracting the first interference signal from the third electrical signal to obtain a third target electrical signal;

    dividing the difference between the first target electrical signal and the third target electrical signal by two to obtain the target electrical signal.
15. The noise reduction method according to claim 13, wherein the method further comprises:

    acquiring a fourth electrical signal of the second beam passing through the first beam delivery loop and the second beam delivery loop during the second delivery time period;

    Wherein, during the second transmission time period, the second light beam is transmitted clockwise in the first light beam transmission loop, while the second light beam is transmitted counterclockwise in the second light beam transmission loop;

    The obtaining the target electrical signal according to the first electrical signal, the second electrical signal and the third electrical signal includes: according to the first electrical signal, the second electrical signal, the third electrical signal The electrical signal and the fourth electrical signal obtain the target electrical signal.
16. The noise reduction method according to claim 15, wherein the target electrical signal is obtained according to the first electrical signal, the second electrical signal, the third electrical signal, and the fourth electrical signal. Signals include:

    subtracting the first electrical signal from the second electrical signal to obtain a first difference;

    subtracting the third electrical signal from the fourth electrical signal to obtain a second difference;

    dividing the sum of the first difference and the second difference by four to obtain the target electrical signal.
17. The noise reduction method according to any one of claims 12 to 16, wherein said generating the first light beam and the second light beam comprises:

    generating a target beam; splitting the target beam into the first beam and the second beam having orthogonal polarization states.
18. The noise reduction method according to any one of claims 12 to 16, wherein said generating the first light beam and the second light beam comprises:

    Generating a target beam with multiple wavelengths;

    splitting the target light beam into the first light beam and the second light beam, wherein the first light beam and the second light beam have different wavelengths.
19. The noise reduction method according to any one of claims 12 to 18, wherein the method further comprises:

    Before the first light beam enters the first light beam transmission loop, measure the power of the first light beam to obtain a first optical power;

    The output power of the light source assembly is adjusted according to the first optical power.

Images